Configuring an Ordered Queue Listener

Name of Ordered Queue (required)

Name of the ordered queue that is used to identify the ordered message listener destination.

Queuing Mode

Determines how received messages are handled. Available modes include:

• immediate. As messages for a group are received, they become available for dispatching.
• batch. A message becomes available for dispatching only when the group is closed.

The default value is immediate.

Sorting Mode

Applies to batch queues only, and only within the batch itself. Available options include:

• Chronological (default). No intra-batch sorting is performed, and the order of presentation to the application is arrival order.
• Lexical. The subsort key is sorted in lexical order. For strings, this is generally considered alphabetic order.
• Numerical. The subsort key is sorted numerically by value rather than as a string.

The default value is Chronological.

Group Timeout

Indicates the time that a batching queue can remain unavailable for dispatching following the receipt of the latest message. In effect, this is an inactivity timeout. The default value is 300 seconds.

Expired Group Flow

Name of a published process flow that receives control if an unended group times out.

Persistent

If enabled, messages are persisted. Persistent messages are held in the safestore until completion and can be recovered if the server is restarted.

Select one of the following options from the drop-down list:

• none {false}
• rdbms {rdbms}
• file {true}

The default value is none {false}.

The rdbms option enables the application to persist messages to a remote database location where, in the event of a failover situation, a secondary server running remotely can continue processing persisted messages without any business interruption.

To use RDBMS persistence, you must create the iway_queues table in the JDBC provider, using the DDL script in the etc/setup directory. A hot backup channel can be configured to use the same RDBMS safestore.

Safestore Location

If persistent, this is the location in the file system to which documents are safestored.

Compress Persistent

If the queue is persistent, the documents written to the safestore can be compressed. Select one of the following options from the drop-down list:

• smallest {best}
• none {none}
• fastest {speed}
• standard {std}

The default option is to not compress (none).

Low Mark

If the size of the named queue falls below this value, then the named listeners that are specified in the Control List parameter are sent an activate message.

The low mark value applies to the queue as a whole, and not to the individual quelelets. The default value is 0.

High Mark

If the size of the named queue goes above this value, then a passivate message is sent to the listeners that are specified in the Control List parameter.

The high mark value applies to the queue as a whole, and not to the individual quelelets. The default value is 0.

Control List

If a high or low mark value is crossed, the appropriate message is sent to each listed listener. For example, if two listeners LISA and LISB are feeding the internal queue, listing them as LISA,LISB will cause each to receive the appropriate message.

Inhibit Add

If set, the queue will not accept new messages when its size reaches the high mark, and will resume accepting messages when the number of messages on the queue reaches the low mark. The effect of this inhibition can cascade through the application, controlling overall performance. The default value is false.

External Mark

When set to a number greater than 0, this causes the message to be stored in memory up to the specified number. When the queue grows larger than the specified number, the message is stored on disk. This is equivalent to splitting the memory and performance optimization for the messages in the queue, and is effective for large lists that may fill memory. The default value is 0.

Duration

Maximum time in seconds (allows xhxxmxxs format) that a document can remain in this channel, starting from when the document is added to the queue, including pends and retries. The default value is 24 hours.

Support Pending

If set, messages can be pended for later execution if the process flow calls for a Fail/Pending operation. Pending messages persist for a specified time and are retried at a specific interval. You might use a pending operation in the event that a message cannot be processed because an external resource is currently unavailable. The default value is false.

Retry Interval

Determines the interval (in seconds) between retrying pending requests. The default value is 600 seconds (10 minutes).